Antique Dealers: 1% of sales revenue, for everything sold which includes Ivory in its manufacture, given to a wildlife fund, and marked on an invoice as such, with a seal, and with a certificate presented (or some kind of paperwork) to that dealer everytime a sale is made, and to show the dealer as having participated in a 'give back' scheme.
Auctioneers: 1% of final hammer price including commissions, for anything which includes Ivory in its manufacture, given to a wildlife fund, and marked on an invoice as such, with a seal and a certificate presented to that auction house.
A voluntary agreement, not mandatory.
What's the win?
* Wildlife funds gets extra funding (Enables further protection for Elephants);
* Dealers / Auctioneers give back to a wildlife protection fund (Something dealers etc. would all take pride in doing, including clients);
* Dealers / Auctioneers get to stay in business;
* Collectors and custodians of art works get to keep their pieces, which hold their value.